The present invention relates to computer managed communication networks and particularly to ease of use interactive computer controlled display interfaces to networks such as the Internet. More particularly, the invention relates to the caching of received document pages or Web pages received at a receiving display station on the network.
The 1990""s have been marked by a technological revolution driven by the convergence of the data processing industry with the consumer electronics industry. Like all such revolutions, it unleashed a significant ripple effect of technological waves. The effect has, in turn, driven technologies which have been known and available but relatively quiescent over the years. A major one of these technologies is the internet-related distribution of documents, media and programs. The convergence of the electronic entertainment and consumer industries with data processing exponentially accelerated the demand for wide ranging communication distribution channels, and the World Wide Web or Internet which had quietly existed for over a generation as a loose academic and government data distribution facility reached xe2x80x9ccritical massxe2x80x9d and commenced a period of phenomenal expansion. With this expansion, businesses and consumers have direct access to all matter of documents, media and computer programs. As a result of these changes, it seems as if virtually all aspects of human endeavor in the industrialized world require human-computer interfaces. Thus, there is a need to make computer directed activities accessible to a substantial portion of the world""s population which, up to a year or two ago, was computer-illiterate, or, at best, computer indifferent. The challenge of our technology is to create display interfaces to computers and particularly to Internet which are intuitive and forgive any impreciseness on the part of users.
With all of these rapidly expanding functions of Web pages and like documentation, it should be readily understandable that the demand for Web documents has been expanding exponentially in recent years. World Wide Web pages are now extensively used for commercial, academic and entertainment purposes. In addition, because of the vast amount of information potentially available through networks such as the internet, it is important that the presentation of the pages of a transmitted document be presented as quickly as possible on the display screen of the receiving display station and with as little effort as possible on the part of the receiving user. To this end, the Internet browser programs through which these users access the Internet are provided with caching capabilities at the receiving display station.
At this point, in order to better understand the factors associated with browsers and caching, a brief review of the current Internet background should be helpful. The most commonly used method of accessing and distributing data over the Internet is through the World Wide Web (WWW) environment commonly known as the xe2x80x9cWebxe2x80x9d.
In the Web environment, servers and clients conduct Web transactions using the Hypertext Transfer Protocol (HTP), a common protocol for handling the transfer of various data files (e.g. text, still graphic images, audio, motion video, etc.). Information is formatted for transfer and presentation to a user by a standard page description language (Hypertext Markup Language (HTML)). Besides formatting, HTML allows developers to specify xe2x80x9clinksxe2x80x9d to other Web resources identified by a Uniform Resource Locator (URL). The URL defines a communication path to an Internet server containing specific logic blocks of information known as Web pages. Web pages may be of any arbitrary size and may include text, graphics, forms for making queries to databases on the server etc. A Web page may include all files required to present the information requested by using the URL identifier, including text/HTML files, graphics files and audio files.
Retrieval from the Web is accomplished with the above-mentioned browser which is an HTML compatible application program for submitting requests for data through a URL submitted by the receiving or client display station. When such data is retrieved, the controlling Web browsers cache pages accessed at the receiving display station. Network bandwidths are finite and the time required to retrieve a Web page depends on the number of servers at the site from which the Web page is being retrieved, the connection speeds and line widths. Also, Web pages often include large graphic files requiring a substantial amount of transfer time from the source to the requesting display station. Furthermore, caching of pages permits the user to repeatedly view the information within a session without also repeatedly retrieving such information from the Internet. The Web pages and pages of other documents retrieved from the Internet cached in the local memory at the receiving display station, usually in cache portions allocated in the local disk drive and in the local random access memory (RAM). Most conventional Internet browsers have programming routines for evaluating incoming documents and allocating local disk drive storage and RAM for the document cache at the receiving display station. Such evaluations and allocations are based in part on the type and size of the files of data supporting the displayed pages. In addition, received files often contain control code indicative of cache size requirements which may be used by the browser to allocate disk drive storage and RAM portions for caching. However, all of these cache allocation procedures presuppose that the user in setting up the browser has set aside sufficient disk drive portions and RAM portions for such caches. For example, let us assume that the browser application using control information provided by an incoming Web page has determined that the document will require a cache having m megabytes of disk space and n megabytes of RAM. However, as it turns out, the user in setting up the browser application has set aside less that the n megabytes of RAM. The browser will attempt to load the document in the RAM cache, since there will be insufficient RAM cache available, the document will be loaded in the noncache portion of RAM. This will, of course, subvert the purpose of the cache in that the document will not be cached to speed up the subsequent document loading, etc.
Conventionally, many browser programs ask the user during set up to specify the quantity of RAM and the quantity of disk drive storage that he wishes to set aside for cache. Since a major portion of Internet and other network access terminal users are relatively unsophisticated in computer arts, this presents difficulties to such users.
The present invention offers a solution to this problem by tracking the prior activity of the user in network accessing, and uses this activity to automatically set aside appropriate RAM and disk drive storage for caching. This concept should be distinguished from automatic cache size determining systems such as that described in U.S. Pat. No. 5,257,370, which tracks the usage of specific files and then stores along with the file control code indicative of the size of disk cache needed to most optimally handle the particular file.
The present invention relates to a computer controlled display system for displaying documents, and particularly for displaying Web pages and related documentation on receiving display workstations in a computer managed communication network. Users access these Web pages via a plurality of data processor controlled interactive display stations, which receive documents transmitted to said display stations from locations remote from said stations. Such documents include a sequence of at least one display screen page containing text and images. The present invention provides for the automatic sizing of the cache for received pages at the receiving display station. This cache includes portions of the station""s disk storage means and RAM means for storing data representative of received screen pages.
The receiving display station also includes means for determining the size of the portions of disk storage means and of the random access storage means for said cache which comprises means for monitoring the quantities of disk storage and of RAM used in said cache during prior transmission of screen pages to said receiving display station, and means for sizing the portions of disk storage and RAM allocated to the present cache based upon said monitoring. These sizing means are most effectively included in a network interactive browser.
The period of prior transmission over which the quantities of disk storage and RAM used in the cache is monitored is preferably one session. Although what constitutes a session will vary from user to user, let us consider one session to be period from which the user enters the Internet and explores several sites in a relatively continuous manner. The session period would be terminated by either the user getting off the Internet or interrupting his browsing for a substantial period of time. Of course, the period of sampling the size of prior caches may be shorter or longer than the previous session.